Interpretive Summary: Advances in genetic research have opened the door to rapid discovery and analysis of genes that regulate vital biological functions. One important tool for identifying gene function in organisms such as insects is the transposon-based gene transfer. In this technique, a small amount of DNA containing a gene of interest is inserted into the insect using the transfer system. We have shown that we can also attach the genes that establish eye color to this small amount of DNA in the red flour beetle. As a result, a change in insect eye color serves as a strong indicator that the new DNA material has been inserted into the genetic structure of the beetle. This provides us with a unique tool for locating hundreds of potential pathways that can be attacked to control the red flour beetle and other pest insects.

Technical Abstract:
The use of eye-color mutants and their corresponding genes as scorable marker systems has facilitated the development of transformation technology in Drosophila and other insects. We decided to exploit endogenous eye-color markers in Tribolium castaneum for development of gene transfer technologies for beetles. To begin correlating eye-color mutations with their respective genes, the Tribolium orthologs of the Drosophila eye-color genes vermilion (tryptophan oxygenase) and cinnabar (kynurenine 3-monooxygenase) were cloned and characterized. Conceptual translations of Tc vermilion (Tcv) and Tc cinnabar (Tccn) are 71% and 51% identical to their respective Drosophila orthologs. Tight linkage was found between Tcv and the white-eye mutation white, here renamed vermilion white (vw). Molecular analysis indicates that 80% of the Tcv coding region is deleted in vw beetles. These observations indicate that Tcv is potentially useful as a germline transformation marker.